Wireless mobile communication technology uses various standards and protocols to transmit data between a base station and a mobile communication device. Wireless communication system standards and protocols can include the 3rd Generation Partnership Project (3GPP) long term evolution (LTE); the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard, which is commonly known to industry groups as WiMAX (Worldwide Interoperability for Microwave Access); and the IEEE 802.11 standard, which is commonly known to industry groups as WiFi. In 3GPP radio access networks (RANs) in LTE systems, the base station can be a combination of Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node Bs (also commonly denoted as evolved Node Bs, enhanced Node Bs, eNodeBs, or eNBs) and Radio Network Controllers (RNCs) in an UTRAN or E-UTRAN, which communicates with the mobile communication device, known as user equipment (UE). A downlink (or DL) transmission can be a communication from the base station (or eNB) to the mobile communication device (or UE), and an uplink (or UL) transmission can be a communication from the mobile communication device to the base station.
In LTE networks, base stations may use spatial multiplexing to increase data rates. Specifically, spatial multiplexing is a transmit scheme that allows a base station having multiple transmit antennas to simultaneously transmit independent and separately encoded data streams from each of the transmit antennas using the same transmit resources. For example, using spatial multiplexing, a base station that uses orthogonal frequency division multiplexing (OFDM) may transmit independent and separately encoded data streams from each of multiple transmit antennas using the same sub-carriers in the same OFDM symbol periods.